Restore backup to new device: can I restore to an older HA Core version?

Installation
1

I‘m going to migrate hardware using a full backup (precisely: a partial backup containing everything except two Addons which are restored separately later) from the old system. HA OS image is running on the new device, ready to restore.

At Onboarding Home Assistant - Home Assistant I read „Home Assistant downloads the latest version of Home Assistant Core (about 700 MB).“.

My current system does not run the latest HA Core version (Supervisor and HA OS are up to date).

QUESTIONS:

  • Will the new system after restoring the full backup run the HA Core version part of the backup?
  • Or will it upgrade HA Core to the latest version during restoring?

Maybe the additional, technically precise question is: what of HA Core actually is part of the backup (only config, right? The docker container itself runs the version).

Interestingly different parts of the community give answers being the opposite of the answers the others give :slight_smile:

So hopefully once and forever someone can give precise technical explanations on that.

1 Like
2

The core version will be whatever your backup contains.

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3

How? Let’s say:

  • The target system contains 2025.2.x, automatically downloaded when HA OS got prepared.
  • The backup contains HA settings from old system running 2024.x.x.

Does the supervisor on the target system load the 2024.x.x image during backup restore and that way take care the config/settings actually being part of the backup match the HA Core docker image?

4

The core version contained in your backup overwrites whatever version it is being written to.

That’s how some people downgrade when things go wrong with an upgrade. Restore a backup from a previous version.

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5

Note that this will not downgrade the operating system. That will remain at whatever HAOS version the system was before restoring the backup.

If you need to downgrade that as well you can do it from the CLI before restoring the backup.

Also the Supervisor version will update automatically.

The core version however is whatever is contained in the backup.

6

That’s great news. I made sure HA OS is on the same version on source and target machine, same for Supervisor.

Good to know there‘s no need to match HA Core versions too and the newer version on the target machine will get overwritten with the (older) version from source machine‘s backup.

Therefore no need to

  • neither update source machine‘s HA Core to latest version
  • nor downgrade the target‘s machine HA Core to the version of the source machine

Thanks a lot for confirming what I was hoping for.

7

Migration experience

Well well well… always great to precisely prepair and plan an action (like a hardware migration) for days and then run into a really really REALLY bad and completely unexpected issue.

…like Supervisor not being able to restore a partial backup.

Currently after powering up the old hardware again and cleaning the last bits of the full data disk to have enough space for a single full backup, it is currently creating the full backup, which I’ll hopefully be able to restore completely on the new hardware. Already lost additional 3 to 4 hours because of this. Priceless.

This is really a bummer in terms of trusting the backup/restore process. Great to have backups! Too bad if you can not restore them.

(I also noticed some things were missing like network shares, content of shares like backup or /config/tts etc. - will dig through those minor issues once the system has been migrated… finger’s crossed.)

Hopefully this - in my eyes major issue - will somehow soon get resolved. Being able to restore only parts (like a specific addon) is an urgent basic feature one needs to be able to trust. I used that in the past a few times, dunno what broke it, maybe a Supervisor update.